Deodato - 5:11 am on Apr 6, 2005 (gmt 0)

My take on this is that:
+ Under IPv4, IP addresses are in very short supply - although some hosts certainly do have large reserves.
+ Anything that encourages webmasters to seek dedicated IP addresses is unsustainable until IPv6.
+ Google's 'do no evil' position would make it hard to justify some algo component that encourages unsustainable behaviour.

Take a look at hosts out there using clustered server architectures - efficient use of resources, high reliability and tens of thousands of domains under a single IP.

If I were Google, I would think long and hard before penalising that.